Brake shoe



NOV. 7, 5 WHWWORTH I BRAKE SHOE Original Filed Dec. 15, 1927 2 Sheets-Sheet 1 IN VEN TOR. 57mm E) h/w-rvamfi BY W A TTORNEV Nov. 7, 1933. 5 WHITWQRTH 1,934,460

BRAKE SHOE Original Filed Dec. 15, 1927 2 Sheets-Sheet 2 I IIIllIII/I/IIII/I/II Ill/[[1117 III/III INVEN TOR. EMA/LEV WI/TWURTH A TTORNEY Patented Nov. 7, 1933 UNITED STATES 1,934,460 7 BRAKE snon smiley Whitworth,

South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend, Ind., a corporation of Delaware Original application December 15, 1927, Serial No.

240,175. Divided and 1932. Serial No. 603,

12 Claims.

This invention relatesto brake shoes, and is described in connection with the construction of a novel shoe folded from a fiat sheet-metal blank, and adapted for use in an internal expanding automobile brake. An object of the invention is to form a light but extremely strong shoe, or the like, preferably by folding it from flat sheet steel in a novel manner, giving it what may be regarded as a laminated structure.

In the arrangement illustrated, the shoe is folded or pressed from a novel blank having, at one or both sides, series of tongues, preferably trapezoiclal in form. In the best arrangement the tongues of one series are staggered with respect to those of the other series, and in folding the shoe the joints between the blank to form a tongues of each series are bridged and connected by the tongues of the other series, although in the broader aspects of the invention these joints may be bridged by'other means connecting the tongues. The center of the blank, which is generally rectangular in form, constitutes the friction face of the finished shoe, and is ordinarily formed-on a cylindrical arc.

In order to fasten the two series of tongues together to form a double-thickness stiffening web for the shoe, it is usually best to fold portions of the blank under the opposite sides of the central position so that the cylindrical part of the finished shoe is also of double thickness. I prefer to fold the blank as described above, prior to bending it to form it on the desired arc.

The blank may, if desired, be formed with one or more portions, which may for example be extensions of tongues at the end of the shoe, and which project beyond the end of the generallyrectangular central portion of the blank, and. which form pivot or anchor arms in the finished shoe, and also with an integral extension which forms in the finished shoe a thrust part or cam plate extending crosswise of the shoe.

The above and other objects and features of the invention, including various novel and desirable details, will be apparent from the following description of the construction of the shoe illustrated in the accompanying drawings, in which:

Figure 1 is a plan view of one form of blank for the shoe;

Figure 2 is a side elevation of the blank after it is formed into a T shape in cross-section;

Figure 3 is a side elevation of the shoe, after it is finished except for the attachment of the lining, etc.;

this application April 7, 866

Figure 4 is a section through the shoe on the line 4-4 of Figure 3;

Figure 5 is an inside elevation of part of the which are preferably generally trapezoidal in form,i. e. the sidesof the openings 18 between the tongues diverge outwardly. I consider it highly desirable that the tongues of the two series should be staggered with respect to each other, i. e. that the tongues 16 of the upper series should be opposite the openingsl8 of the lower series, and vice versa. The two tongues 16 'at one end of the blank may, if desired, be extended as integral projections 20 which form pivot arms in the finished shoe. The illustrated blank also has an integral projection 22 at the other end, which forms a thrust part or cam plate in the finished shoe.

The blank is first folded into a straight member, such as shown in Figure 2, which is T-shaped in cross-section as shown in Figure 4. This may be done all in one folding operation, or the tongues 16 may be folded 90 in one direction about the dotted lines 24, after which the side portions 12 and 1e are folded 180 in the opposite direction about dotted lines 26. In either case the partly-finished shoe of Figure 2 is obtained, with the same general cross-section as the finished shoe, but straight instead of curved cylindrically and with openings 18 still remaining between the tongues 16.

The shoe is then rolled or pressed into cylindrical arcuate form, the openings 18 being eliminatedby bringing the tongues 16 substantially edge to edge. The joint between each adjacent pair of tongues 16 in one of the series of tongues is bridged by one of the tongues 16 of the other series, since as explained above the tongues of the two series are staggered with respect to each other. While held in this cylindrical form, the two series of tongues are permanently secured together, for example by projection-welding or by ordinary spot-welding, thus forming a doubleside portions 12 and 14, and series of tongues 16' thickness stifiening web for the shoe. An opening 28 may be punched in the pivot arm 20, to receive a bushing or be otherwise formed and arranged to be mounted on a pivot or anchor, and an opening 30 may also if desired be formed to provide clearance for the pivot or anchor of an adjacent shoe.

The tongue, 22, if provided, is foldedacrossthe end of the stiffening web, as shown in Figure .6, to provide a thrust member for engagement with a cam or other applying device. Another arrangement for this purpose is shown in Figure 7 where the two end tongues 16 diverge from each other to provide a trussed support for a tongue 1'22 bent crosswise of the shoe. The tongue 122 may,

if desired, be arc-welded at its end to the opposite tongue 16.

The shoe made as described above, completed except for the pivot or anchor bushing ordinarily used in the opening 28 and except for the friction lining (shown however in dotted lines at 32 in Figure 4), is shown in Figures 3-'7.

While one illustrative embodiment has been described in detail, it is not my intention to limit the scope of the invention to that particular embodiment, or otherwise than by the terms of the appended claims.

This application is a division of my copending application entitled Brake shoes, filed December 15, 1927 and Serial No. 2%,1'75.

I claim:

1. A brake shoe having a double-thickness stiffening web comprising two series of tongues staggered with respect to each other and secured together with the joint between successive tongues in one series bridged by one of the tongues of the other series.

2. ,An arcuate brake shoe having a doublethickness stifiening web comprising two series of trapezoidal tongues staggered with respect to each other and secured together with the joint between successive tongues in one series bridged by one of the tongues of the other series.

3. A brake shoe having a double-thickness cylindrical outer portion and adouble-thickness stiffening web formed of tongues secured together.

generally-trapezoidal 4. A brake shoe having a stiffening web formed of tongues secured together edge to edge.

5. A brake shoe having a series of tongues forming a stiifening web, and having means bridging the joints between successive tongues and securing them together.

6. An arcuate brake shoe having a series of tongues arranged substantially edge to edge to form a stiffening web, and having means bridging the joints between successive tongues and securing the tongues together.

7. A brake shoe having a series of tongues forming a stifiening web, and having means bridging the joints between successive tongues and securing them together, at least one tongue at one :end of the shoe being extended to form a pivot arm.

s. An arcuate brake shoe having a series of generally-trapezoidal tongues arranged substan tially edge to edge to form a stifiening web, and having means bridging thejoints between successive tongues and securing the tongues together, at least one tongue at one end of the shoe being extended to form a pivot arm.

9. Abrake shoe having adouble-thiclmess stifiening web comprising two series of tongues staggered with respect to each other and secured to gether with the joint between successive tongues in one series bridged by one of the tongues of the other series, two of the tongues at one end of the shoes being extended to form a doublethickness pivot arm.

10. A brake shoe having a stiffening web formed of tongues securedtogether edge to edge, two of the tongues at one end of the shoe being extended to form a double-thickness pivot arm.

11. A brake shoe having a double-thickness stiffening web, with one thickness having a portion folded twice crosswise of the end of the shoe to form a double-thickness thrust part.

12,.A brake shoe having a double-thickness stiffening web, with one thickness having a portion folded crosswise of the end of the shoe to form a thrust part, the other thickness being arranged in supporting engagement with said thrust part.

STANLEY WHITWORTH. 

